JPS5821414A - Thermosetting resin composition - Google Patents

Abstract

PURPOSE:The titled composition, containing a specific imido group-containing isocyanate, polyfunctional isocyanate, a silanol group-containing silicone and an isocyanate trimerization catalyst, and having improved heat resistance and wide applicability. CONSTITUTION:(A) An imido group-containing isocyanate, having isocyanate groups at the molecular terminals, and obtained by reacting a carboxylic acid anhydried, e.g. trimellitic anhydride, in which at least two of three or ore carboxyl groups present in the molecule form an acid anhydride ring with a polyfunctional isocyanate, e.g. methane diisocyanate, in chemical equivalent exceess is mixed with (B) a polyfunctional isocyanate, (C) a silanol group-containing silicone at an equivalent ratio of preferably 19:(20-50):(2-10). (D) An isocyanate trimerization catalyst, e.g. an N-substituted morpholine compound, in a given amount is then mixed therewith, and the resultant mixture is directly heated or reacted under preheating and heated at 80-250 deg.C for 1-50hr to give the aimed composition.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thermosetting resin composition that produces a cured product with heat resistance class 0 (180°C) or higher, and more specifically, the present invention relates to a thermosetting resin composition that produces a cured product with heat resistance class 0 (180°C) or higher, and more specifically, cures to cure incyanurate ring bonds, imide bonds, and silicone The present invention relates to thermosetting resin compositions that produce resins having bonds in their chemical structure.

There are strong demands for electrical equipment to be smaller and lighter, larger in capacity, and improved in reliability, and there is a demand for the development of insulating materials with better heat resistance.

Conventionally, research into heat-resistant materials has progressed mainly in the field of solvent-based varnishes for enameled wires or laminated materials, and excellent materials such as polyimide, polybenzimidazole, polyamideimide, silicone, and polydiphenyl ether have been developed.

The mainstream method for these materials is to increase heat resistance by introducing a heterocycle into the molecular structure.

However, when a heterocycle is introduced into a molecule, the viscosity becomes high and the material generally becomes solid, so a solvent is required when these materials are used as a varnish. In such solvent-based varnishes, the solvent evaporates during curing and tends to leave a large amount of voids, so compared to solvent-free varnishes, they have poor heat dissipation, low voltage resistance, low adhesive strength, poor moisture resistance, and are susceptible to thermal deterioration. It has drawbacks such as being thick. For this reason, it is very important that the insulating varnish for electrical equipment be a solvent-free type that does not contain any solvent.

Epoxy resins are currently being used as solvent-free varnishes that have relatively excellent heat resistance, but the maximum operating temperature of general epoxy resins is limited to 180°C. Solvent-free silicones are attracting attention because of their good thermal stability, but their use is limited due to their low strength at high temperatures. On the other hand, polyimide originally has a heat resistance of 300°C or higher, but in order to make it a solvent-free varnish, a hetero component was introduced from the beginning, as seen in maleimide materials or imide epoxy materials, and low molecular weight compounds were added. is the raw material. Therefore, the original heat resistance of polyimide is significantly reduced, and its heat resistance is limited to 200°C at most.

By the way, incyanurate oxazolidone resin (see Japanese Patent Publication No. 52-31000) and imide resin, which are made of polyfunctional incyanate and polyfunctional epoxy compound as main raw materials, are used as varnishes that relatively achieve both low viscosity and heat resistance. Imide incyanurate oxazolidone resin (see Japanese Patent Publication No. 53-47277), whose main raw materials are a group-containing polyfunctional incyanate and a polyfunctional epoxy compound,
be. These resins have heat resistance imparted by an incyanurate ring and an imide ring, and mechanical properties, particularly flexibility, by an oxazolidone ring. However, since all of these contain an oxazolidone ring with low heat resistance, their heat resistance is limited to 220° C., and further improvement in heat resistance is desired.

The present invention was made in view of the above-mentioned current situation, and by heating in a solvent-free type, a resin having incyanurate ring bonds with excellent heat resistance and imide bonds and silicone bonds with excellent heat resistance and flexibility can be produced. It is an object of the present invention to provide a novel thermosetting resin composition that can be converted by curing.

The thermosetting resin composition of the present invention that achieves the above object is (
a) A molecule obtained by reacting a carboxylic acid anhydride in which at least two of the three or more carboxyl groups present in the molecule form an acid anhydride ring with a chemically equivalent excess of polyfunctional incyanate. Imide group-containing incyanate having an isocyanate group at the end, (b) polyfunctional isocyanate), (e) silanol group-containing silicone, and ri
(a) It is characterized by containing an incyanate trimerization catalyst.

The reaction and structural formula of the imide group-containing isocyanate, which is component (a) of the present invention, are as follows when the carboxylic acid anhydride is pyromellitic dianhydride.

0 0 (wherein R represents a divalent organic group constituting the polyfunctional incyanate, m, n, and p are positive numbers, and m ) n. ) The closer the equivalence ratio m/n to Kava, the higher the degree of polymerization of the product. In addition, p is preferably 1 to 3 in view of compatibility with the components of misfortune.

In addition, when the carboxylic acid anhydride is tricarboxylic acid monoanhydride, the product is represented by the following general formula (n) (wherein R1p has the same meaning as in formula Examples of polyfunctional functional cyanates used in component (a) of the present invention include methane diisocyanate, butane-1,1-diisocyanate, ethane-1,2-diincyanate, butane-1, 2-diisocyanate, transvinylene diisocyanate, furopane-1,3-
Diisocyanate, butane-1,4-diisocyanate, 2-butene-1,4-diisocyanate, 2-methylbutane-1,4-diisocyanate, pentane-1,5
-diisocyanate, 2,2-dimethylpenta7'-1
, 5-diincyanate, hexane-1,6-diisocyanate, heptane-1,7-diisocyanate, octane-1,8-diisocyanate, nonane-1,9-diincyanate, decane-1,10-diincyanate, dimethylsilane Diisocyanate, diphenylsilane diisocyanate, ω, m'-1,3-dimethylbenzene diisocyanate, ω, ω'-1', 4-dimethylbenzene diisocyanate, ω, ω'-1,3-') methylcyclohexane diisocyanate, ω, ω'-1.4
-dimethylcyclohexane diincyanate, ω, ω'
-1,,4-dimethylbenzene diisocyanate, ω,
tjJ'-1,4-dimethylnaphthalene diisocyanate, ω,ω'-1,5-dimethylnaphthalene diisocyanate, cyclohexane-1,3-diisocyanate, cyclohexane-1,4-diisocyanate, cyclohexylmethane-4,4'-diisocyanate ,1,
3-phenylene diisocyanate, L'゛-phenylene diisocyanate, 1-methylbenzene-2,4-diisocyanate, 1-methylbenzene-2,5-diisocyanate, 1-methylbenzene-2,6-diisocyanate, 1-methyl Benzene-3,5-diisocyanate, diphenyl ether-4,4'-diisocyanate,
diphenyl ether-2,4'-diisocyanate, naphthalene-1,4-diisocyanate, naphthalene-1
, 5-diisocyanate, biphenyl-4,4'-diisocyanate, 3,3'-dimethylbiphenyl-4,4
-diisocyanate, 2,3'-dimethoxybiphenyl-a, 4'-diisocyanate, diphenylmethane-4
, 4'-diisocyanate, 3.3'-dimethoxydiphenylmethane-4,4'-diisocyanate, 4.4-
Difunctional isocyanate compounds such as dimethoxydiphenylmethane-3,3'-diisocyanate, diphenylsulfide-4,4'-diincyanate, diphenylsulfone-4,4'-diincyanate, polymethylene
Tri- or higher-functional incyanate compounds such as polyphenyl isocyanate, triphenylmethane triincyanate, tris (4-phenylisocyanate thiophosphate), and 3.3', 4.4'-diphenylmethane tetraisocyanate can be mentioned.

Also, 2. of these incyanate compounds. # body, trimer,
Alternatively, a liquid isocyanate obtained by converting a portion of 4,4'-diphenylmethane diisocyanate into carbodiimide may also be used.

Examples of the carboxylic anhydride used in component (a) of the present invention include hatrimetic anhydride, pyromellitic dianhydride, 1,2,3.4-benzenetetracarboxylic dianhydride, 5.5' , 4,4'-benzophenonetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, cyclopentanetetracarboxylic dianhydride, ethylene glycol bis(trimellitate)
Examples include dianhydride, glyceryltris(trimelitate) trianhydride, and the like.

In producing the imide group-containing in'yanate of the present invention by the reaction exemplified by the above formula (I), the polyfunctional isocyanate must be used in chemical equivalent excess with respect to the carboxylic acid anhydride (. However, the polyfunctional incyanate and the carboxylic acid anhydride are not limited to one type of compound each, and a mixture thereof may be used.

To explain specifically about the production of imide group-containing incyanate, the imide group-containing isocyanate, which is the reaction product of formula (1), is mixed with a carboxylic acid anhydride and a stoichiometrically excess amount of polyamide with respect to the carboxylic acid anhydride. Functional incyanate can generally be synthesized by heating at room temperature to 200°C for 4 to 200 hours in a dry inert gas flow, but the reaction conditions depend on the properties of the carboxylic acid anhydride and polyfunctional isocyanate. , is not necessarily limited to the above. Also, if necessary, N.

Solvents such as N-dimethylacetamide ρ, hexamethylphosphoramide, N-methylpyrrolidone, dimethylsulfoxide, phenol, and cresols may also be used.

The progress of the reaction can be tracked by observing the bubbles of carbon dioxide gas generated, and the reaction is allowed to continue until no bubbles are generated. If carboxylic acid anhydride remains unreacted, bubbles may be generated during the process of converting into a heat-resistant resin while forming incyanurate bonds, which may have an adverse effect on electrical properties. It is necessary to react to form an imide group.

In the present invention, the equivalent ratio of polyfunctional isocyanate to carboxylic anhydride is preferably in the range of 2 to 50, although it depends on the functional number of the reaction system. When the charging equivalent ratio is 2 or less, carboxylic acid anhydride tends to remain unreacted. In addition, heat resistance tends to deteriorate in the range where the charging equivalent ratio is small (1)
There it is. Furthermore, if the charging equivalent ratio exceeds 50, the properties of the cured product tend to become extremely brittle.

Examples of the polyfunctional incyanate that is component (b) of the present invention include the same compound as the polyfunctional incyanate that is component (a) described above, and those that are the same as or different from that of component (a) may be used. However, it will be understood that it does not include incyanates containing imide groups.

Component (1) may be separately blended in the reaction mixture V of component (a), but the unreacted polyfunctional incyanate in the reaction mixture of component (a) is used as it is as component (1). can do.

The silanol group-containing silicones as component (C) of the present invention include general formulas R81X3, R25iX2, R35iX
(In the formula, R represents a hydrogen atom, a methyl group, an ethyl group, a phenyl group, etc., or a hydrolyzable group such as a halogen atom, an alkoxy group, etc. f) Blending silanes in a composition according to the purpose, Water is added to this to hydrolyze it, and then the silicone group bonded to the silicon atom is partially dehydrated and condensed with heat or in the presence of a catalyst to appropriately increase the degree of polymerization. Such silicones containing silanol groups are commercially available, such as KR-272 (silanol group content: 2 t), manufactured by Shin-Etsu Silicone Co., Ltd., and KR-275 (silanol group content: 0.5 to
1ch), KR-214 (4ch as above), KR-216 (6% as above), KR-215 (5-6q6 as above), etc. can be used as appropriate. Among these, KR-215, KR-
A solvent-free type such as No. 216 is preferred.

The silanol group-containing silicone reacts with the free isocyanate groups of components (a) and (1)) and is incorporated into the cured product, contributing to heat resistance and flexibility, as shown in item 2) below.

(R'' represents the organic group of component (a) or component (b), and R'' represents the silicone bone core.) The blending ratio of the three components in the present invention is (a)/
(b) The equivalent ratio of 7 (c) is preferably 10/1
0-100/1-20, more preferably 10/20-5
It is 0/2 to 10. If the proportion of imide group-containing incyanate and silanol group-containing silicone is small, it tends to become brittle, and if it is too large, heat resistance tends to deteriorate.

The incyanate trimerization catalyst which is component (d) of the present invention includes alkali acetate JJ such as sodium acetate and calcium acetate, alkaline earth metal salts, alkali metal alcoholades such as sodium methoxide and sodium ethoxide, ferric chloride, etc. , magnesium chloride, nickel chloride, tin chloride, lead nitrate, copper naphthenate, metal salts of lead, zinc, cobalt, nickel, manganese, etc., copper octenoate,
Metal salts such as lead, zinc, cobalt, nickel, manganese, etc.
Organotin compounds such as tetra-n-butyltin, tri-n-butyltin acetate, dimethyltin dichloride, dibutyltin dilaurate, dibutyltin-di-2-ethylhexoate, and similar iron, magnesium, nickel, tin, zinc, Metal salts such as lead and metal compounds, 2,4.6-tri(dimethylaminomethyl)phenol, 4,6-di(dimethylaminomethyl)phenol, 2,4-dimethyl-6-dimethyl-6-dimethyl Mannich base of phenols such as aminomethinophenol, trimethylamine, triethylamine, tetramethylbuta/diamine, tetramethylpentanediamine, tetramethylhexanediamine, triethylenediamine,
Tertiary amine compounds such as dimethylaminoethanol and dimethylaminopentanol, N-methylmorpholine,
N-substituted morpholine compounds such as N-ethylmorpholine, N-dodecylmorpholine, butylene dimorpholine, hexamethylene dimorpholine, cyanoethylmorpholine, triazinoethylmorpholine, 2-methylimidazole, 2-ethylimidazole, 2- Undecylimidazole, 2-hebutadecylimidazole, 2-methyl-4
-ethylimidazole, 1-butylimidazole, 1-
Propyl-2-methylimidazole, 1-benzyl-2
-Methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-(4゜6-'/7mi/-s-
) 'J Azinyl-2-ethyl-2-methylimidazole, 1-(4,6-diamitu-s-triazinyl-2
-ethyl)-2-ethyl-4-methylimidazole, 1
Examples include imidazole compounds such as -(4,6-diamitwo-8-triazinyl-2-ethyl)-2-undecylimidazole. Among the above catalysts, N-substituted morpholine compounds and imidazole derivatives are particularly effective. At least one of the above catalysts may be used in an amount ranging from 0.01 to 10% of the incyanate compound. A range of 0.1 to 2% by weight is particularly desirable. If the amount is less than this range, the curing time will tend to be too long, and if it is too much, the properties of the cured product will tend to deteriorate.

Known additives, fillers, pigments, solvents, etc. can be added as necessary. As mentioned above, the thermosetting resin composition is solvent-free, so it can be used as a variety of materials.
It cures easily by heating for 0 hours and has excellent heat resistance that allows it to be used for long periods of time even at high temperatures of 240°C or higher.

In addition, the resin after curing has excellent crack resistance, electrical properties, chemical resistance,
Because it has excellent self-extinguishing properties, it has a wide range of uses, including heat-resistant insulating varnish, casting resin, molding resin for electronic parts, laminating resin, printed wiring resin, and interior material resin.

Next, the present invention will be explained with reference to Examples, but the present invention is not limited to these in any way. The polyfunctional incyanate compounds, acid anhydride catalysts, and silanol group-containing silicones indicated by the abbreviations used in the following examples are as follows.

MDI: 4,4'-diphenylmethane diisonanate (equivalent weight 125).

I, -MDI: MDI that is partially carbodiimidated and is liquid at room temperature (equivalent weight: about 140).

PMDA: pyromellitic dianhydride.

BPDA: 5,5',4,4'-benzophenone tetracarboxylic anhydride.

211i4MZ: 2-ethyl-4-methylimidazole.

NMM: N-methylmorpholine.

KR215: Manufactured by Shin-Etsu Silicone Co., Ltd. KR215: Silanol group content 5-6% KR216: Manufactured by Shin-Etsu Silicone Co., Ltd. KR216: Silanol group content 6% Example 1 PMDA 10. OtrO, 046 mol), M
D1114F (0,4/+mol) and dehydrated N,N-
Dimethylacetamide 143F (152d) was placed in a four-loaf flask equipped with a stirrer, thermometer, and reflux condenser.
The reaction was allowed to proceed for 10 days at room temperature in a stream of dry nitrogen. Then 90℃
N,N-dimethylacetamide was distilled off under reduced pressure (-
1 reactant (hereinafter referred to as incyanate<AJ) was obtained.

The infrared absorption spectrum of this product shows absorption based on isocyanate groups at 2260 cm'', 1780 cm'',
Absorption based on imide groups was observed at 1730 cm'' and 720 cm''1.

The above-mentioned isocyanate (A) is a mixture of the reaction product shown in the above-mentioned reaction formula (I) and unreacted incyanate, and was used as it is in blending other components.

Isocyanate) cA) 100 fVcKR2161
7,32 and NMM O,5fi were added and mixed well to obtain a composition. This material was heated to 110°C for 15 hours.
Next, 15 hours at 150°C, 10 hours at 200°C, 2
A cured product was obtained by heating at 40°C for 10 hours while gradually increasing the temperature.

In the infrared absorption spectrum of this cured product, the absorption based on the isocyanate group at 2260 cm-1 that existed before curing disappears, and the absorption based on the isocyanurate bond (1710 cm-1) disappears.
absorption of m"-' and Si-0-Si at 1050 cm"
Absorption based on Also based on imide group (1780
cm"", 1730 cm-" and 720 cm-1
No change was observed in the absorption of This revealed that the cured product was a polymer mainly having incyanurate bonds, imide bonds, and silicone bonds.

The obtained cured product was a reddish-brown transparent resin, and the weight loss initiation temperature of this cured product in a nitrogen atmosphere was 400°C.

Moreover, the mechanical properties and electrical properties of this cured product are very excellent as shown in Table IVC below.

Table 1 Examples 2 to 11 BPDA 14.8 ta (0,046 mol), L-
MDll 28.89 (0.46 mol) and dehydrated dimethylacetamide 1431F (152td) were reacted in the same manner as in Example 1 for 10 days. The reaction product contains unreacted incyanate as in Example 1. The catalysts shown in Table 2 were added to the reaction products 100f and KR2159f, respectively, and mixed well to obtain various compositions.

The compositions of Examples 2 to 11 were heated at 110°C for 15 hours, then at 150°C for 15 hours, at 200°C for 10 hours, and at 240°C.
A cured product was obtained by heating at C for 10 hours. As in Example 1, the infrared absorption spectra of these cured products include:
Absorption based on incyanurate bonds, imide bonds, and silicone bonds was observed fc. The obtained cured product was a reddish-brown, transparent resin, and the weight loss initiation temperature of this cured product in a nitrogen atmosphere was 680 to 450°C. Also, the electrical properties of this cured product showed excellent &C characteristics similar to those of Example 1.

Furthermore, the mechanical properties of this cured product are shown in Table 3, showing excellent heat resistance.

Examples 12 to 18 PMDA and MDI used in Example 1 were blended at the mixing ratios shown in Table 4, and otherwise reacted in the same manner as in Example 1 at room temperature for 10 days. Dimethylacetamide was distilled off under reduced pressure from this reaction product 1, this reaction product 100 f
, KR21615? A resin composition was prepared by mixing NMMo and 5P.

This resin composition was heated at 110°C for 15 hours and at 150°C for 1 hour.
The mixture was heated for 5 hours, at 200°C for 10 hours, and then at 240°C for 10 hours with gradual heating to obtain a cured product. This cured product is a reddish-brown transparent resin whose infrared absorption spectrum is almost the same as in Example 1, and it is believed that these cured products are mainly polymers having incyanurate bonds, imide bonds, and silicone bonds. Understood. All of the resins obtained in Examples 12 to 18 exhibited substantially the same electrical properties as those of Example 1. Furthermore, the mechanical properties are shown in Table 4, showing excellent heat resistance properties.

As shown in Example 12, when the equivalent ratio of polyfunctional incyanate/acid anhydride is 1.5, the tensile strength is low and thermal deterioration is large, and the tensile strength becomes zero after heating at 270°C for 15 days, making it impossible to obtain a satisfactory product. There wasn't. Further, as shown in Example 18, when the equivalent ratio of polyfunctional incyanate/acid anhydride is 70, the tensile strength is low and it is brittle. On the other hand, as shown in Examples 13 to 17, the equivalent ratio of isocyanate group/acid anhydride is 2 to 5.
It can be seen that 0 has good high temperature strength and heat resistance.

Example 19 60°C1 without using dimethylacetamide and without solvent
An experiment was conducted under the same conditions as in Example 1, except that the reaction was carried out for 10 days. In the infrared absorption spectrum of the obtained cured product, absorption based on isocyanurate bonds, imirr° bonds, and silicone bonds was observed. The obtained cured product was a reddish-brown transparent resin, and its mechanical properties and electrical properties showed excellent properties similar to those of Example 1.

Example 20 Imide group-containing incyanate obtained in Example 1 <A) 60
f, KR21610f, MDI 40f and NM
A composition was prepared by mixing Mo and 5f.

This composition was heated at 110°C for 15 hours, at 150°C for 15 hours, at 200°C for 10 hours, and further at 240''C for 10 hours to obtain a cured product.

This cured product was a reddish-brown transparent resin, and its infrared absorption spectrum showed absorption based on isocyanurate bonds, toimide bonds, and silicone bonds. The electrical and mechanical properties of this cured product showed excellent properties similar to those of Example 15.

Comparative Example 1 Novolac type polyglycidyl ether (manufactured by Dow Chemical Company, DEN438, Epoquin per i 190) 1
009. Methylendomethylenetetrahydro anhydride, phthalic acid (manufactured by Hitachi Chemical, MHAC-P) 66 F and 2-
Ethyl-4-methylimidazole (Shikoku Kasei 2E4M)
Z) 0.89 was blended and mixed well, and this mixture was added to 1
A cured product was obtained by heating at 10''C for 5 hours, 150°C for 10 hours, and 225°C for 15 hours.The temperature at which this cured product started to lose weight in a nitrogen atmosphere was 285°C, which is the novel heat of the present invention. The temperature was about 120°C lower than that of the curable resin composition.

The mechanical properties and electrical properties of this cured product are as shown in Table 5. Although this composition has the best heat resistance among epoxy resins, it exhibited extremely poor heat resistance and electrical properties compared to the novel thermosetting resin composition of the present invention.

Table 5 Comparative Example 2 Diglydyl ether of bisphenol A (DIRJ32, manufactured by Dow Chemical Company, USA, epoxy equivalent: 174) 100?
, MDI 174g and NMMO, 27f were mixed well. This mixture was heated to 110°C for 5 hours and 150°C for 10 hours.
The mixture was heated at 225°C for 15 hours to obtain a cured product. The bond reduction starting temperature of the obtained cured product in a nitrogen atmosphere is 3
Approximately 20° compared to the novel thermosetting resin of the present invention at 80°C
It showed a low C value. The mechanical properties and electrical properties of this cured product are as shown in Table 6. Table 1 As is clear from the above description, the thermosetting resin composition of the present invention provides a cured product with excellent heat resistance, which has not been achieved even with conventional isocyanurate oxazolidone resins, and is solvent-free. Since it is a type resin composition, it has the advantage of wide applicability.

Patent applicant: Hitachi, Ltd. Agent Hiroshi Nakamoto

Claims (1)

[Claims] 1. (a) A polyfunctional polyfunctional compound in which at least two of the three or more carboxyl groups present in the molecule are chemically equivalent to the carboxylic acid anhydride forming an acid anhydride ring. It is characterized by containing an imide group-containing incyanate having an incyanate group at the molecular end obtained by reacting with isocyanate, (b) a polyfunctional isocyanate, (C) a silanol group-containing silicone, and (d) an isocyanate trimerization catalyst. A thermosetting resin composition. 2. The chemical equivalent ratio of (a) imide group-containing isocyanate, (b) polyfunctional isocyanate, and (C) silanol group-containing silicone is 10/10 to 100.
/1 to 2q. The thermosetting resin composition according to claim 1.